DESCRIPTION: The overall goal of the research program described in this grant application centers around the development of near infrared (NIR) spectroscopic chemical sensors for clinical and biomedical measurements. This novel sensing strategy offers the potential of continuously and noninvasively monitoring important clinical analytes in complex biological matrices. The proposed research is a collaboration between Professor Mark Arnold (University of Iowa), who will focus on the instrumental development aspects of the research, William Sivitz (Clinical Research Center, University of Iowa), who will focus on evaluation of the device on patients, and Professor Gary Small (Ohio University), who will focus on the data treatment. The emphasis of the research detailed in this proposal is the continued development of a noninvasive blood glucose sensor that can be used in the control and daily treatment of diabetes. Results are provided that illustrate the first demonstration of a valid blood glucose calibration model generated from noninvasive spectra. Experiments are proposed to improve the analytical performance of this system by enhancing both the quality of the NIR spectra and the data analysis algorithms used to extract the glucose information from the spectral information. A research strategy is proposed to establish the utility of both individual and global calibration models for in situ blood glucose levels. In addition, a series of novel NIR chemical sensors is proposed for continuously monitoring the process of hemodialysis. Sensing units are described for measuring urea accumulation in the dialysate fluid, urea and total protein in the newly dialyzed blood, and in situ levels of urea, total protein and albumin in the patient s body. This last group of sensors is based on noninvasive sensing strategies. These sensors will provide information that is not presently available to the practicing physician and this information can be used to: (1) establish and administer the ideal dialysis dose at every dialysis session; (2) improve patient nutrition; (3) avoid dialysis complications; and (4) prevent vascular access thrombosis. All of these features will have an instant impact on the morbidity and mortality of each patient undergoing dialysis.